Clutch mounting



J. VASTA CLUTCH MOUNTING Nov. 7, 1939.

Filed July 13, 1958 gll/ L/oSf/D/ M45 7A INVENTOR wg.. i

BY ATTORNEYS.

Illu

Patented Nov. 7, 1939 srres entrar einer;

CLUTCH MOUNTING i Joseph Vasta, New York, N. Y.

Application July 13, 1938, Serial No. 219,026 1 Claims.v `(Cl. 192-110) This invention relates to clutches `and mountings therefor of the type used for driving sewing machines by an electric motor.`

One of the principal problems of such a clutch SSeCurflg the alignmentof the driven member of the clutch and the motor shaft. Faulty alignment causes vunsatisfactory operation and excessive wear on all `parts of the driving mechanism, including the motor bearings.

yl0 `To 'overcome this difiiculty motors are now supplied with a `special casing of motor and clutch,` with intertting parts accurately machined so that the motor and clutch `fit together in alignment. This is a relatively expensive l5 product, as compared with one which can be used with any standard motor, A

Other clutches for use with standard motors have means for adjusting the bearings of the driven member into alignment with the motor shaft, but `thefcon'xplexity of the adjustments is such as to make perfect alignment diicult t secure.

In accordance with my invention the align` ment is assisted by axial guide devices on the driving and driven members', which serve to align the driven member with respect to the motor shaft While its bearing bracket is being i'lxed to the motor base.

The accompanying drawing shows two illustrative forms of the invention. 5

Fig. 1 is a side elevation of a sewing machine clutch and motor, parts of the clutch being shown in section;

Fig. 2 is a plan view of the unit shown in Fig, l, with the bearing bracket of the driven mem` ber in the position in which it is placed to slip the clutch parts together; and i Fig. 3 is a detail longitudinal sectional view of a modified formv of clutch. 5

Figs. 1 and 2 showa motor base I8 to which a motor M is attached by bolts l2 passing through slots i4 in the motor base I0 and slots i6 in the cradle i8 of the motor. The base l0 is attached to the cloth "board 20 of the sewing machine by screws 22.

The base Iii has an arm 24 to which a .bearing bracket 26 is attached by a bolt 28. The bolt passes `through a slot 3i! in lthe bearing bracket and is screwed into a threaded hole in the arm 24. A tongue 32 on the arm 24 ts into a groove 34 between two ribs 35 of the bracket arm 28. The sides 38 of the tongue 32 and the sides 48 of the ribs 36 are bevelled to make a firm fit of the bearing bracket to the arm 24. The bevelled faces 38 and 40, when clamped together by the bolt 28, oppose movement of the bearing bracket with respect to the arm 24 in every direction except one perpendicular to the motor shaft. The clutch comprises two friction members 5 42 and 44. `The member 42 has an axial bore it vwhich snugly fits the'pprotruding end 48 of the motor shaft. A `hub EQ on the member 42 is bored to lreceive a setscrew 52 which serves to secure it to the shaft 48. 10

The clutch member 44 has an axial bore 54 into which a shaft 55is driven so that these parts' become a solid unit.. The member 44 has aconical friction face 58 which coacts with a friction band El), preferably in the form of a 15 square leather strap, which is partially laid into a groove t2V in the conical face 64 of the clutch member 42. `The bearing bracket has bearings viii and 58 to receive the shaft 58. Preferably a compression `spring 'i8 is inserted between the 20 bearing 66 and a collar l2 fixed by a setscrew 'i4 tc the shaft 58, to hold the shaft normally to the left, so that its friction face 58 is out of contact with the friction band till. The bearing 68 has an arm 'it on which a lever 'i8 is rock- 25 ably mounted by a screw Sil. The lever 'i8 has a setscrew `il? screwed into its left-hand arm, where its end t4 stands opposition to the end of shaft 56. A spring 3S normally pulls the lever away from the shaft 5t and a link 8i? extends 30 to `a pedal (not shown) by which the lever can be operated to thrust the driven member comprising the shaft 5t and disk 44 against the clutch member 42.` A brake shoe Sii may be provided on the lever 'lll tostop the disk 44 when 35 it moves out of engagement with the clutch member ft2. A belt pulley 92 is fixedby a screw 534 to a hub Slt of disk 4d. A belt 92 runs from this pulley up to a pulley on the main shaft of the sewing machine (not shown) in the usual 40 manner. A ber washer lili may be provided to take the 'thrust of the clutch, this washer being inserted between the face of the adjacent end bearing of the motor shaft and the h ub 58 of the clutchmember 42. 45

In accordance with the present invention the alignment of the driven member comprising the shaft 5S and disk `i4 with the motor shaft 48 is 56 is slipped into the socket formed by that part of the bore 46 not occupied by the shaft 48. This automatically determines the correct position of the driven member with respect to the clutch member 42 and this position is retained by throwing the bearing bracket 25 over into Contact with the arm 24 and clamping the parts together by the bolt 28. As the bolt is tightened up the clutch member 42 can be spun by hand to assure freedom of movement between the two parts of the clutch. The fit between the end |92 of shaft 56 and the bore 46 can be quite free without impairing the effectiveness of these guiding parts in aligning the driven member with the friction member 42. That is to say, there may be considerably greater play between these parts than could be allowed if they were to serve as bearing surfaces. Since they serve only as an aligning means and the bearing bracket fixed to the base plate thereupon takes up the function of holding the driven member in alignment with the motor shaft, a bearing t of the shaft end E02 in the bore 4'6 is not required. The tongue and groove faces on the bearing bracket and the arm 24 prevent relative movement of the bearing bracket and the arm 24 in all directions, but one perpendicular to the motor shaft, which is the direction required for adjustment to different sizes of motor. Extreme accuracy in machining of the bevel faces 38 and 40 is not required, inasmuch as the position of the motor cradle I8 upon the base l0 can be adjusted if necessary to meet a slight discrepancy in alignment in the horizontal plane. The simplest way to do this is to allow the motor to run for a short time with with the bolts l2 loosened, so that it can settle naturally into the correct position. It is necessary to have the faces 38 and 40 exactly perpendicular to horizontal planes containing the axes of the motor shaft 48 and driven shaft 56, respectively.

Oil cups |04 and |06 are provided for oiling the respective bearings 56 and 68. A central bore |08 in shaft 56 carries oil to the bore 4'6.

Fig. 3 shows a reversal of the arrangement shown in Fig. l. The motor and bearing bracket and base plate are the same for this modification, the only difference being in the clutch members. The friction member 42a is xed to the motor shaft 48 by a setscrew 52 passing through its hub 50a. The driven member comprises a disk 44a driven upon a shaft 56a and having a conical bearing face 58a. The clutch member 42a has a conical face 64 bearing a friction band 60a. In this case the bore 54a of the disk 44a is somewhat longer than the protruding portion of the shaft 56a, to provide a socket receiving a shaft H0205 extending axially from the member 42a. In other respects the devices are similar, that of Fig. l being preferred because it is simpler to manufacture.

I claim:

In a device of the class described, a motor, a

base upon which said motor is mounted, a driving member comprising the shaft of said motor and a friction element fixed to said shaft, a driven member comprising a shaft and a friction element fixed thereto and adapted to bear against the friction element of said driving member, a bearing bracket in which the shaft of said driven member is rotatably mounted, means for detachably securing said bearing bracket to said base, said last means being adjustable in a direction perpendicular to the axis of the shaft of said driven member, one of said members having an axial socket, the other of said members having an axially protruding shaft adapted to slide into said socket to align said members when said bearing bracket is mounted on said base.

JOSEPH VASTA. 

